bidiv(1) Ivrix bidiv(1)
NAME
bidiv - bidirectional text filter
SYNOPSIS
bidiv [ -plj ] [ -w width ] [file...]
DESCRIPTION
bidiv is a filter, or viewer, for birectional text stored in logical-or-
der. It converts such text into visual-order text which can be viewed on
terminals that do not handle bidirectionality. The output visual-order
text is formatted assuming a fixed number of characters per line (auto-
matically determined or given with the -w parameter).
bidiv is oriented towards Hebrew, and assumes the input to be a Hebrew
and ASCII text encoded in one of the two common logical-order encodings:
ISO-8859-8-i or UTF-8. Actually, bidiv guesses the encoding of its input
at a character by character basis, so the input might be a mix of
ISO-8859-8-i and Hebrew UTF-8. bidiv's output is visual-order text, in
either the ISO-8859-8 or UTF-8 encoding, depending on your locale set-
ting.
bidiv reads each file in sequence, converts it into visual order and
writes it on the standard output. Thus:
$ bidiv file
prints file on your terminal (assuming it has the appropriate fonts, but
no bidirectionality support), and:
$ bidiv file1 file2 | less
concatenates file1 and file2, and shows the results using the pager
less.
If no input file is given, bidiv reads from the standard input file.
For more ideas on how to use bidiv, see the EXAMPLES section below.
OPTIONS
-p Paragraph-based direction (default): When formatting a bidirec-
tional output line, bidiv needs to be aware of that line's base
direction. A line whose base direction is RTL (right to left)
gets right-justified and its first element appears on the right.
Otherwise, the line is left-justified and its first element ap-
pears on the left.
The -p option tells bidiv to choose a base direction per para-
graph, where a paragraph is delimited by an empty line. This is
bidiv's default behavior, and usually gives the expected results
on most texts and emails.
The direction of the entire paragraph is chosen according to the
first strongly-directioned character (i.e., an alphabetic charac-
ter) appearing in the paragraph. Currently, if the first output
line of a paragraph has no directional characters (e.g., a line
of minus signs before an email signature, or a line containing
only numbers) that line is output with the same direction of the
previous paragraph, but it does not determine the direction of
the rest of the paragraph. If the first line of the first para-
graph does not have a direction, the RTL direction is arbitrarily
chosen.
-l Line-based direction: This option choose an alternative method of
choosing each output line's base direction. When this option is
enabled, the base direction of each output line is determined on
its own (again, according to the first character on the line with
a strong direction). This method may give wrong results in the
case where a line starts with a word of the opposite direction.
This case is rare, but does happen under random line-splitting
circumstances, or when the text is defining words of a foreign
language.
-j Do not justify: By default, RTL lines are right-justified, i.e.,
they are padded with spaces on the left when shorter than the re-
quired line width (see the -w option). The -j option tells bidiv
not to preform this justifications, and leave short lines un-
padded.
-w width
bidiv formats its output for lines of the given width. Lines are
split when longer than this width, and RTL lines are right-just-
fied to fill that width unless the -j option is given.
When the -w option is not given, bidiv uses the value of the
COLUMNS variable, which is usually automatically defined by the
user's shell. When that both the -w option and the COLUMNS vari-
able are missing, the default of 80 columns is used.
OPERANDS
The following operand is supported:
file A path name of an input file. If no file is specified, the
standard input is used.
EXAMPLES
1. bidiv README | less
2. man something | bidiv | less
(or groff -man -Tlatin1 something.1 |sed 's/.^H\(.\)/\1/g' |../bidiv
-w 65)
3. set "bidiv" as a filter for your mail program (mutt, pine, etc.) for
viewing mail with the ISO 8859-8-i character set, and Hebrew UTF-8
mail.
ENVIRONMENT
COLUMNS see -w option.
EXIT STATUS
The following exit values are returned:
0 All input files were output successfully.
>0 An error occurred.
AUTHOR
Written by Nadav Har'El, http://nadav.harel.org.il.
Please send bug reports and comments to nyh@math.technion.ac.il.
The latest version of this software can be found in
ftp://ftp.ivrix.org.il/pub/ivrix/src/cmdline
SEE ALSO
cat(1), fribidi(3)
Bidiv 7 Jan 2006 bidiv(1)
Generated by dwww version 1.16 on Sat Oct 3 04:49:07 CEST 2026.